Network operators interconnect their autonomous system networks (ASNs) through some mix of Internet transit relationships, where a fee is paid for a network to carry traffic, and peering relationships, where fees are substantially avoided, forming the Internet. Turning to FIG. 1A, Internet traffic can flow by various methods. Traffic originating at a source autonomous network or first network 100 can access resources of a destination within a destination autonomous system network or a second network 118 via several methods.
First, the first network 100 can send traffic originating from its source router 102 via a network communications link 104 to a first transit provider autonomous systems network (“first transit provider”) 106. The first transit provider 106 would then direct said traffic via a series of internal or external routers 108, 112 that are connected to one another via one or more network communications links 110 at the discretion of the first transit provider 106. The traffic is then sent directly to the destination router 116 of the second network 118 via a network communications link 114. Furthermore and at the discretion of the first transit provider 106, traffic could also be directed via network communications link 136 to one or more additional transit providers in series 138, 140, 142, 144 via their respective network communication links 146, 148, 150, in which such traffic is controlled at the discretion of the first transit provider 106 before reaching the destination router 116 within the second network 118 via network communications link 152.
Second, the first network 100 can direct traffic through an intermediate Internet Exchange Point (IXP). An IXP is a physical infrastructure through which Internet Service Providers (ISPs), Content Delivery Networks (CDNs) and Enterprise networks exchange traffic between their autonomous system networks. The primary purpose of the IXP is to allow autonomous system networks to interconnect directly, via the IXP, rather than through one or more third-party networks. The advantages of directing traffic through an intermediate IXP interconnection are numerous and include improvements in cost savings, latency, bandwidth and routing control.
A typical IXP includes one or more Ethernet-based local area network (LAN) switches housed in a single location or interconnected across multiple locations. The IXP operates in a layer-2 configuration and utilizes an IP subnet for the connection of participating autonomous system networks. While these very design choices have made the traditional IXPs useful, the IXPs are centralized in their uses or applications.
The second method of accessing resources of the second network 118 is also shown in FIG. 1A. The known first network 100 can direct traffic from the source router 102 over a network communications link 120 to an IXP 122. The IXP 122 directs the traffic through the IXP switch fabric 124 to the network communications link 126 and to the destination router 116 of the second network 118.
Finally, the known first network 100 can establish a private interconnection network communications link 134 directly with the second network 118 for the purpose of sending traffic between them, as also shown in FIG. 1A.